Some rocks according to their use or texture are classified into different types. Know more about Gabbro Texture and Mylonite Texture. Types of Gabbro are Not Available whereas the types of Mylonite are Blastomylonites, Ultramylonites and Phyllonites.During historic times, some rocks depending on their hardness were used to create Pictographs and Petroglyphs. Rocks which are hard were generally not used. Pictographs are paintings or drawings that have been placed or created on the surface of rock. Gabbro was not used to create pictographs whereas Mylonite is used to create pictographs. Petroglyph is an image which is carved into a rock. These are images created by removing part of a rock surface by incising, picking, carving or abrading, as a form of rock art. Gabbro was not used to create petroglyphs whereas Mylonite was used to create petroglyphs.